James w



(No Model.) A

J. W. HAYFORD.

DENTAL MOLD.

No. 296,690. Patented Apr. 8, 1884.'

1 @may wlmfssf Nrrnp Arsr JAMES EV. HAYFORD, OF TIFFIN, OHIO, ASSIGNOR @POKE-HALF TO GEORGE S. YINGLING, OF SAME PLACE.

DENTAL MOLD.

SPECIFICATION forming part of Letters Patent No. 296,690, dated April 8, 18S-i.

Application tiled November 2, 1883. (No model.)

To all whom it 11i/ty concern:

Be it known that I, Jar-ins W. Harrer-rn, a citizen of the 'United States, residing at Tiilin, in the county of Seneca and State of Ohio,

have invented certain new and useful Improvements in Dental-Plate Molds, of which the following is a specication, reference being had therein to the accompanying drawings.

This invention relates to certain improveio ments in dental molds; and it has l'or its object to provide for the formation of a casting as nearly as possible free from blemishes, and is designed, principally, to be used in .making castings of light metal, such as aluminium.

i5 This object I attain by the means illustrated in the accompanying drawings, in which- Figure l represents a vertical sectional view of a mold constructed according to my invention, and Fig. 2 a detached view of a portion no of the devices for clamping the parts of the mold together.

The letter A indieates a-iiat metallic plate,

v provided with an inverted- U-shaped metallic standard or frame, B, through the top of which,

at the center, extends a screw, C, which has at its upper end awhecl, l), by means of which it may be turned. The said screw, at its lower end,

has swiveled to it a metallic plate, E, which is adapted to set between the lugs F on the top 3o of the upper section, Gr, of the mold, for the purpose more fully hereinafter set forth.

The letterH indicates a metallic plate adapted to set upon the base before mentioned, and to be secured thereto by means of the clamps I, which clasp the lugs K at opposite sides of the said plate. To the said lugs are secured hollow metallic standards, which are slotted vertically, as shown.

The letter Lindicatesa short metallic cylinder, which rests upon the plate H, and which is provided with lugs M, which set in the slots in the standards, so as to hold the plate in position. The said cylinder or ring forms a portion of the lower section of the mold. The

upper section of the mold consists, in part, of an inverted cylindrical cup, which is also provided with lugs to set in the slots in the standards, so as to cause the two sections to register and, hol-d them relatively in proper 5o position for casting.

The letter N indicates a metallic ring or annulus, to be embedded in the plastic material',

'which forms a portion of the lower section of which is to form part of the up per mold-section, and which is to be embedded in the plastie material therein, the said ring being adapted to iit over the first-mentioned ring when in place, as4 clearly shown in the drawings. The metallic cup or sh ell of the upper mold-section is provided with apertures S and T, which lead to ports or gates formed in the plastic material of said upper section, one for .the admission of molten metal and the other for the escape of air, as will be explained in the following description of the operation of my invention.

The operation of my invention is as follows: An impression is taken from the mouth and a model made in the saine manner as for rulcanite work. A rim of wax is formed around the edges of the lower mold-section, and the plastic mixture is poured in until it reaches the edges of said rim. Then, before setting, the model is pressed into the plaster a sufficient distance, and the lower ring is pressed into the plaster around thc model about one-third of its width, or far enough to admit of the placing on it of the larger upper ring. The second 0r larger ring is then placed on the smaller ring, (the wax rimhaving been removed,) after which the upper section of the mold is iilled with plaster, and is pressed down upon the lower section. 7When set, the sections may be separated and the model removed, and after the formation ofthe gates and ventsthe moldis complete. The molten metal is run into the mold by any suitable means, and when the lower section thereoi` is full the mechanical means to secure the desired pressure are applied to further force the metal into the cavities of the mold and compress and solidly complete the casting of the plate. Then the metal of the plate has cooled suiiiciently, the iiask is opened and the formed plate removed for further treatment in the hands of the de'ntist. The rings forni a tight or parti ally-ti ght flask, or, rather,

IOO

a deep welhwhieh holds the metal, and allows cape through the vents.

Having thus ldescribed my invention, what I claim, and desire to secure by Letters Patent7 is- 1. The combination, with the base-plate and frame of the device7 of the bottom plate and shell forming the lower section of the mold7 the lateral lugs on said bottom plate having slotted guide-standards for the sections of the mold and the slotted clamps, whereby the bottom plate is clamped to the base of the mold, substantially as specified.

2. In combination with the upper and lower sections of the mold and the frame, and bottom plate guide standards and pressurescrew, the internal rings adapted to fit one within the other and be embedded in the respective matrices ofthe mold, one of the rings 'being slotted at its edges for the initial escape of gas or confined air, substantially as specied. Y

3. The combination, with the frame and its base, of the mold-sections, the bottom plate and slotted guide-standards and clamps, and the pressure-screw having a dovetailed swiveled plate, and the dovetailed projections on the upper section of the mold,with which said plate engages, whereby the upper section may be manipulated accurately with respect to the lower section, substantially as specified.

In testimony whereof I affix my signature in presence of twowitnesses.

JAMES XV. I-IAYFORD.

lVitnesses:

Giro. S. YINGLING, HARRY TOMB. 

